Association between cancer and selenium concentration in blood and toenails

Rhee, Jung Kil; Chung, Jong Hak; Sakong, Jun; Kang, Pock Soo; Kim, Chang Yoon; Lee, Kyeong Soo; Kwon, Koing Bo

Abstract

A case-control study was conducted to investigate the association between the risk of cancer and selenium concentration in blood and toenails. Seventy three patients and two hundreds eighty three controls were selected at the Yeungnam University Hospital between May and September in 1991. The selected cases were patients who had been hospitalized for stomach or colon cancer at the Department of General Surgery. The controls were people who visited to check physical examination at the Automated Mediscreening Center. The selenium concentration in whole blood and toenails were measured by atomic absorption spectrophotometer equipped with graphite furnace atomizer. The following information was ascertained for all cancer patients and controls: sex, age, body mass index, blood pressure, total serum cholesterol, and history of smoking and drinking. The mean selenium concentration in blood and toenail for all cancer patients were 143.6±10.8 µg/l and 1.04±0.62 µg/g and for the controls. 167.0±14.5 µg/l and 1.15±0.55 µg/g, respectively. The difference in blood and toenail selenium concentrations of the two cancer sites was not statistically significant. Metastasis did not influence the concentration of selenium in blood and toenails. In the multiple logistic regression analysis, the blood selenium concentration (aOR: 0.888, 95% CI: 0.860-0.918), age, BMI and total serum cholesterol were significant variables for risk of cancer, but the selenium concentration in toenail was not shown to be a significant variable in this regression analysis. The coefficient for blood selenium concentration adjusted for age, sex, diastolic blood pressure, total serum cholesterol, body mass index and smoking was -0.1184 (p<0.01). These findings suggest that low selenium concentration is associated with gastrointestinal cancers. Further epidemiologic studies including important variables such as other antioxidant micronutrients will be necessary.